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Atrial Septal Defect In Dogs

Atrial Septal Defect In Dogs

What is Atrial Septal Defect In Dogs?

An atrial septal defect (ASD) is a hole in the septum (wall) between the two atrial chambers, the two smaller chambers at the top of the heart. The interatrial septum defect allows the blood to get "shunted" from the left atrium to the right because of the rather high pressure of the blood (after the oxygen has depleted) that returns from the rest of the body and causing a volume overload of the right-sided chambers.

Sometimes with elevated right atrial pressure (Pulmonary stenosis), shunting may happen from right to left through a patent foramen ovale (hole between the left and right atria) or atrial septal defect, resulting in polycythemia and cyanosis.

The pathogenesis depends on the size of the defect, the size of the shunt, the ratio of pulmonary to systemic vascular resistance, and the comparative conformity of the two ventricles.

An ASD can be located in different parts of the atrial membrane and can be of any size.

Thankfully, most the ASD dogs are not severely affected. This condition is rare in dogs, accounting for less than 3% of all congenital heart defects. Most the dogs live have few or no symptoms and many have normal life spans.

Symptoms Of Atrial Septal Defect In Dogs

Signs of congestive heart failure (CHF) may be present.
  • Heart murmur
  • Exercise intolerance
  • Increased respiratory rate
  • Cyanosis
  • Intermittent cough
  • Fluid accumulation in the lungs (pleural effusion), within the lungs (pulmonary edema), and abdomen (ascites).

Treatment Options For Atrial Septal Defect In Dogs

Treatment is not required for dogs that are asymptomatic and those having a good quality of life.

Surgery in ASD dogs is riskier and rarely done with conditions that aren’t life-threatening though surgery is routine in humans with ASD. You may go for frequent check-ups to assess if the problem is getting worse.

Medical management for Dogs with mild symptoms may be necessary to support heart function and reduce congestive heart failure.

Home Remedies For Atrial Septal Defect In Dogs

Every breed of dog is different and indeed every individual dog is different in its own right.

This means that the best home remedies (such as diets) for your dog undergoing treatment for heart disease– depending on your dog.

This needs patience on your part as it is likely to be a case of trial and error to find the best home remedies that are most suitable for your dog with heart disease.

Work with your vet to find the optimal dietary plan for your dog.

Home remedies such as herbs, diet, and exercise will depend on your dog’s age, the type of heart disease, and the stage of the disease they are in.

How to Prevent Atrial Septal Defect In Dogs?

Prevention of ASD is a hereditary concern. Dogs with ASD including First degree relatives (littermates and parents) should not be bred so as to avoid passing the condition on to the next generation.

Screening of highly affected breeds prior to breeding is strongly recommended.

Affected Dog Breeds Of Atrial Septal Defect

Standard Poodle, Boxer, Doberman Pinscher, Old English Sheepdog, Samoyed

There is no sex predisposition.

Additional Facts On Atrial Septal Defect In Dogs

In the animal embryo, the heart fails to grow properly and a hole in the wall separating two of the chambers of the heart may remain open. These right and left atriums are instrumental in pumping blood into the lungs and the rest of the body.

In atrial septal defects, the blood gets "shunted" from the right side to the left due to relatively high pressures as deoxygenated blood returns from the rest of the body. Consequently, blood does not get pushed into the lungs properly, resulting in insufficient oxygen in the blood and an increase of non-oxygenated blood backing up in the rest of the body.

Depending on where the defect is located, there are 3 different types of ASD

  • Ostium Secundum – Most common and considered a true defect. The hole occurs in the central part of the atrial septum (fossa ovalis).
  • Ostium primum (AV canal defects or endocardial cushion defects) bottom of the atrial septum close to the ventricle chambers
  • Sinus venomous defect – junction of the right atrium and superior vena cava

Veterinary cardiologists say that dogs with severe ASD are those having other heart defects that are likely to have developed in tandem with the defect itself.

Dogs with a severe defect will start to show symptoms within three years of age. Congestive heart failure may develop in ASD dogs once the heart gets weaker.

ASD is a hereditary condition that is considered to be the result of multiple genetic factors.

When To See A Vet For Atrial Septal Defect In Dogs?

The typical approach for this condition is no treatment is needed until symptoms are noted.

Treatment for ASD varies according to the presence of other heart abnormalities and the extent of the defects.

For young, otherwise healthy dogs with a life-threatening defect, surgery may be effective but this will depend on the recommendation of a veterinarian.

Dog Food Suggestions For Atrial Septal Defect

Dietary management of ASD in dogs

  • ASD dogs’ ability to excrete sodium in their urine is markedly reduced. Sodium or salt should be limited to help reduce fluid accumulation.
  • Foods that tend to be high in salt should be cut off. snack foods (crackers, chips, pretzels, etc.), pizza, bread, cheese, other dairy products, etc.
  • Diets elevated in protein (>100 grams per 1000 calories) with at least 30% meat-based protein (on a dry matter basis) are recommended.
  • Amino acid taurine (supplement) is commonly recommended. Some breeds may require more taurine (Boxers, Newfoundlands, Cocker Spaniels, Irish Wolfhounds).
  • Omega-3 fatty acids(fish oils).
  • Vitamin E and co-enzyme Q10.
  • carnitine, B vitamins, and Magnesium.
  • Maintain ideal body weight and Fresh food can be a very healthy option.


It’s never pleasant to hear your dog has heart defects. The prognosis for ASD dogs is much better than with other heart defects. Many ASD dogs can live normal lives if they are without any other complications. Dogs with mild symptoms can be managed with medications.

As a pet owner, you can help out in several ways – by being aware of the symptoms of heart disease, by feeding them the most appropriate diet for them, by working with vets, and by providing them with the treatment they require.

This may not be easy, but it is going to be worth it.

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